Engine fitting and method of assembling vehicles

ABSTRACT

A method of assembling vehicles is provided that includes providing a first engine with a first engine manifold having a first opening, and installing a first fitting in the first opening. A second engine is provided with a second engine manifold having a second opening, and a second fitting substantially identical to the first fitting is installed in the second opening. A seal portion of the first fitting is separated from a body portion of the first fitting at a weakened joint between the seal portion and the body portion. The body portion of the first fitting is then connected with a brake system on a first vehicle to enable vacuum assist of the brake system via a vacuum within the first engine manifold. The second engine is operated without separating a seal portion of the second fitting so that the second opening is plugged by the second fitting.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent application Ser. No. 12/211,294 filed on Sep. 16, 2008, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The invention relates to a method of assembling vehicles.

BACKGROUND OF THE INVENTION

An engine manifold creates a vacuum when the engine is operating. On some vehicles having vacuum assisted brakes, the manifold vacuum is connected with the brake system using an engine fitting fitted to the manifold, and a conduit connecting the fitting with the brake system. To prevent contamination of the engine, the fitting is plugged during shipping and prior to assembly of the vehicle. Engine testing may also be necessary prior to connection with the brake system and/or installation on the vehicle. The plug must be sufficient to withstand engine pressures reached during such testing, yet must be removable by a torque or force sufficiently low to meet workplace guidelines.

Solutions provided for this problem to date have included using a two-piece fitting design, with a removable nylon nipple acting as a plug, slipped over the outside of the body of the fitting. It is difficult to retain the nipple on the body of the fitting under pressures encountered during testing. Additionally, the nipple creates excess waste as a throw-away component. Complex fittings having multiple components that can achieve a sealed state and an open state are available, but tend to be expensive due to their complex design.

SUMMARY OF THE INVENTION

A method of assembling vehicles is provided that allows a fitting for an engine manifold to be used both during vehicle engine testing and during engine use, for vehicles with vacuum assisted brakes and for those without. The method of assembling vehicles includes providing a first engine with a first engine manifold having a first opening. The method then includes installing a first fitting in the first opening. Under the method, the engine may be tested with the first fitting intact such that a seal portion of the first fitting seals the first opening. After any such testing, the method includes separating the seal portion from a body portion of the first fitting at a weakened joint. This may be accomplished by applying a predetermined torque to the seal portion. After separating the seal portion, the method includes connecting the body portion of the first fitting with a brake system on a first vehicle to enable vacuum assist of the brake system via a vacuum within the manifold. Because the fitting withstands normal engine operating pressures without separating or fracturing, the method also includes providing a second engine with a second engine manifold having a second opening, installing a second fitting substantially identical to the first fitting in the second opening. Optionally, the method may include testing the second engine with the seal portion of the second fitting sealing the second opening. After any such testing, the engine is operated on the second vehicle with the second fitting plugging the second opening. A seal portion of the second fitting is thus not separated from a body portion of the second fitting, as the second vehicle does not require vacuum assist to the brake system.

The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional side view illustration of an engine fitting in an opening of an engine manifold shown in fragmentary view, with the engine fitting having a seal portion connected with a body portion via a weakened joint;

FIG. 2 is a schematic cross-sectional and fragmentary view of the engine fitting of FIG. 1 with the seal portion removed by fracture at the weakened joint, and with a tubular fitting shown in phantom connected to fitting;

FIG. 3 is a schematic illustration in perspective view of the engine fitting of FIG. 1;

FIG. 4 is a schematic illustration in end view of the engine fitting of FIG. 3;

FIG. 5 is a schematic illustration in perspective view of the engine fitting of FIG. 4 with the seal portion removed by fracture at the weakened joint;

FIG. 6 is a schematic perspective view of the seal portion of the fitting of FIG. 5 after removal by fracture at the weakened joint;

FIG. 7 is a schematic perspective view of an engine on a first vehicle with the engine fitting of FIG. 2 with seal portion removed supported in the engine manifold and connected to a brake system;

FIG. 8 is a schematic perspective view of an engine on a second vehicle with the engine fitting of FIG. 1 supported in the engine manifold and not connected to a brake system; and

FIG. 9 is a flow diagram illustrating a method of assembling vehicles such as the vehicles of FIGS. 7 and 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, wherein like reference numbers refer to like components, FIG. 1 shows an engine fitting 10, which functions as a dual-purpose component as described herein. The engine fitting 10 is shown at a cross-section taken at lines 1-1 in FIG. 4. The engine fitting 10 is threaded within an opening 12 in an engine air intake manifold 14. Threads 16 on the outer surface of the fitting 10 are apparent in FIG. 3.

The engine fitting 10 is a one-piece, unitary component that is an injection-molded nylon or plastic, such as 33% glass filled nylon, but is not limited to such, and may be any other suitably formed material. The engine fitting 10 has a body portion 18 with an elongated passage 20. The passage 20 has a first end 22 and a second end 24. The fitting 10 also has a seal portion 26, also referred to as a cap or cap portion, that encloses the first end 22. The seal portion 26 is connected or joined with the body portion 18 at a weakened joint 28 formed from of a thinned wall 30. The seal portion 26 has an undercut region 32, also referred to as a recess, that tapers into the seal portion 26 from an outer periphery 34 of the passage 20.

The weakened joint 28 is purposefully formed to establish a fracture region, enabling fracture to occur at the thinned wall 30 by application of sufficient torque to the cap portion 26, separating the cap portion 26 from the body portion 18. Referring to FIG. 4, torque applied to a screwdriver inserted in slot 36 can cause fracture at the thinned wall 30. Alternatively, torque applied by a box wrench fitted to the side surface 38 of the cap portion 26 can cause fracture. The thinned wall 30 is designed so that the amount of torque applied to the cap portion 26 necessary to cause fracture is within a range determined to be ergonomically acceptable for assembly line operations. For example, the thinned wall 30 may have a thickness that is about 15-20% of the thickness t of the surrounding body portion 18. For example, with a thickness t of 1.9 mm, the thinned wall may have a thickness of 0.4 mm to 0.6 mm in order to allow fracture with an applied torque of 10 to 15 Newton-meters.

As shown in FIGS. 2 and 5, the fracture surface 40 of the body portion 18 is substantially at the fracture region 28 and thinned wall 30 of FIG. 1, with little or no flash (i.e., jagged edges) extending from the surface 40. A complementary fracture surface 42 of the cap portion 26 is shown in FIG. 6. The undercut region 32 acts to minimize the flash, e.g., to not greater than 0.13 mm, and enables the relatively clean break or fracture by further localizing stress from the applied torque at the weakened joint 28.

Referring to FIG. 1, the cap portion 26 has a peripheral flange 44 that serves as a support surface for a removal tool applied to the cap portion 26. Additionally, the body portion 18 has an annular ridge 46 that serves to help retain a tubular connection 50, shown in phantom in FIG. 2, fit over the first end 22 after removal of the cap portion 26.

As shown in FIG. 7, the tubular connection 50 connects the fitting 10 with a vacuum assist brake system 52 on a vehicle 54. The vacuum developed in the manifold 14 of engine 56 is used as the vacuum source for the vacuum assist brake system 52.

While allowing removal with a minimal torque, the fitting 10 is configured to withstand engine pressures developed during routine engine testing as well as during engine operation over the lifetime of the engine, without causing fracture at the thinned wall 30 or elsewhere. Thus, the thinned wall 30 will not separate during engine testing. Accordingly, the fitting 10 may be installed on engine 56, tested, and then the cap portion 26 may be removed via torque by a worker or robotically, and the hose 50 connected to the fitting 10 and brake system 52. The fitting 10 is thus a dual-purpose fitting, usable as a plug for opening 12 during engine testing, and usable as a conduit between the manifold 14 and the brake system 52 during operation of the vehicle 54.

Alternatively, because the fitting 10 withstands normal engine operating pressures, it may be retained as-is, as a permanent plug for the opening 12, if installed on an engine in a vehicle that does not require vacuum assist with manifold vacuum for a brake system or other purpose. As shown in FIG. 8, a fitting with cap portion 26A (identical to cap portion 26) intact, referred to as fitting 10A and identical in all respects to fitting 10, is shown installed on vehicle 58 in an opening in manifold 14A of engine 56A, which is identical in all respects to engine 56 of FIG. 7. A brake system 60 on vehicle 58 is not a vacuum assist type. Accordingly, after testing of the engine 56A, the cap portion 26 is not removed.

A method 100 of assembling vehicles, illustrated in the flow diagram of FIG. 9, is discussed with respect to the fitting 10 (and identical fitting 10A) described above. The method 100 includes step 102, providing a first engine 56 with a first engine manifold 14 having a first opening 12. The method 100 further includes step 104, installing a first fitting 10 in the first opening 12. Next, the method 100 includes step 106, testing the engine 56 with the fitting 10 with seal portion 26 sealing the opening 12. After step 106 is complete, the method 100 includes step 108, separating the seal portion 26 from a body portion 18 of the fitting 10 at a weakened joint 28 by applying the predetermined torque to the seal portion 26. After step 108, step 110 may be performed, connecting the body portion 18 with a brake system 52 on the first vehicle 54 to enable vacuum assist of the brake system 52 via a vacuum within the manifold 14.

Because the fitting 10 is configured to withstand engine operating pressures without separating, the method 100 also includes step 112, providing a second engine 56A with a second engine manifold 14A having a second opening 12A. Next, step 114 is performed, installing a second fitting 10A (identical to fitting 10) in the second opening 12A. Step 116, testing the second engine 56A with the seal portion 26A of the second fitting 10A sealing the second opening 12A. After step 116, the method 100 includes step 118, operating the engine 56A on a second vehicle 58 without separating the second seal portion 26A. Thus, the same type of fitting is used for engine testing, and for in-use on both vehicles with brake vacuum assist and those without.

While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims. 

1. A method of assembling vehicles, comprising: providing a first engine with a first engine manifold having a first opening; installing a first fitting in the first opening; wherein the first fitting has: a body portion configured to fit within the first opening and defining a passage having opposing first and second ends; wherein the first end is outside of the first manifold and the second end is inside of the first manifold; a seal portion enclosing the first end of the passage; and wherein the fitting has a weakened joint between the body portion and the seal portion establishing a predetermined fracture region at which the seal portion will separate from the body portion when a predetermined torque is applied to the seal portion to thereby open the first end of the passage; testing the engine with the seal portion sealing the first opening; after testing, separating the seal portion from the body portion at the weakened joint by applying the predetermined torque to the seal portion; and after separating the seal portion, connecting the body portion with a brake system on a first vehicle to enable vacuum assist of the brake system via a vacuum within the first engine manifold.
 2. The method of claim 1, further comprising: providing a second engine with a second engine manifold having a second opening; installing a second fitting in the second opening; wherein the second fitting is substantially identical to the first fitting; testing the second engine with the seal portion of the second fitting sealing the second opening; and after testing the second engine, operating the second engine on a second vehicle without separating the second seal portion.
 3. A method of assembling vehicles, comprising: providing a first engine with a first engine manifold having a first opening; installing a first fitting in the first opening such that the first fitting plugs the first opening; providing a second engine with a second engine manifold having a second opening; installing a second fitting in the second opening; wherein the second fitting is substantially identical to the first fitting such that the second fitting plugs the second opening; separating a seal portion of the first fitting from a body portion of the first fitting at a weakened joint between the seal portion and the body portion to unplug the second opening; after separating the seal portion, connecting the body portion of the first fitting with a brake system on a first vehicle to enable vacuum assist of the brake system via a vacuum within the first engine manifold; and operating the second engine with the second opening plugged by the second fitting.
 4. The method of claim 3, further comprising: prior to separating the seal portion, testing the first engine with the first fitting plugging the first opening.
 5. The method of claim 4, further comprising: prior to operating the second engine, testing the second engine with the second fitting plugging the second opening.
 6. The method of claim 3, wherein the separating is by applying a predetermined torque to the seal portion.
 7. The method of claim 3, wherein the installing the first fitting in the first opening is by threading the first fitting into the first opening at threads of the first opening.
 8. The method of claim 3, wherein the separating includes supporting a removal tool at a support surface of the first fitting.
 9. The method of claim 3, further comprising: configuring the first fitting such that the seal portion will be retained to the body portion without fracture at a manifold pressure not greater than a predetermined amount.
 10. A method of assembling vehicles, comprising: providing a first engine with a first engine manifold having a first opening; configuring a first fitting such that a seal portion of the first fitting will be retained to a body portion of the first fitting without fracture at a manifold pressure not greater than a predetermined amount when the first fitting is installed with the body portion in the first opening and the seal portion sealing the first opening; installing the first fitting in the first opening; testing the first engine with the seal portion sealing the first opening; after testing the first engine, separating the seal portion from the body portion at a weakened joint between the seal portion and the body portion; after separating the seal portion, connecting the body portion with a brake system on a first vehicle to enable vacuum assist of the brake system via a vacuum within the first engine manifold; providing a second engine with a second engine manifold having a second opening; installing a second fitting in the second opening; wherein the second fitting is substantially identical to the first fitting; testing the second engine with a seal portion of the second fitting sealing the second opening; and after testing the second engine, operating the second engine without separating the seal portion of the second fitting so that the second opening remains sealed by the second fitting. 